class RBS::Diff

def each_diff_constants(before_constant_children, after_constant_children)
  all_keys = before_constant_children.keys.to_set + after_constant_children.keys.to_set
  all_keys.each do |key|
    before = constant_to_s(before_constant_children[key]) or next
    after = constant_to_s(after_constant_children[key]) or next
    next if before == after
    yield before, after
  end
end